Refrigerating apparatus



Dec. 3, 1940.

E. J. DILLMAN REFRIGERATING APPARATUS Filed April 9, 1937 5 Sheets-Sheet 1 Fmt] INVENTOR @www M2M/M ATTORNEY Dec. 3, 1940.

E. J. DILLMAN REFRIGERATING APPARATUS Filed April 9, 1937 5 Sheets-Sheet 2 NI/ENTOR AMM/f' BY W v "v M A TTORNEY Dec. 3, 1940. E. J. DILLMAN 2,224,099

REFRIGERA'ING 'APPARATUS Filed April 9, 1937 5 Sheets-Sheet 3 /NI/ENTOR ff@ MW. Mm

@wam/M MJ A TTORNEY' Dec. 3, 1940. E, D|| MAN 2,224,099

REFRIGERATING APPARATUS Filed April 9, 1937 5 Sheets-Sheet 4 rig-7 /NVENTO/e K E5- I vBY 'WX' W m ATTORNEY Dec. 3, 1940. E. J. DILLMAN.- 2,224,099

REFRIGERATING APPARATUS Filed April 9, 1937 5 Sheets-Sheet 5 M ATTORNEY Patented Dec. 3, 1940 PATENT OFFICE REFRIGERATING APPARATUS Earnest J. Dillman, Detroit, Mich., assignor to Detroit Lubricator Company, Detroit, Mich., a corporation of Michigan Application April 9, 1937, Serial No. 135,959

as Claims.

My invention relates generally to refrigerating apparatus and more particularly to refrigerating apparatus of the generator-absorber type.

One of the objectsof my invention is to provide a generator-absorber type of refrigerating apparatus in which the temperature of the evap; orator is positively controlled to maintain the temperature thereof at a desired, substantially constant temperature irrespective of changes in the heat load.

Another object of my invention is to provide a new and improved generator-absorber type of refrigerating apparatus which is eicient in operation,.maintains a substantially constant evaporator temperature irrespective of the heat load, and one inwhich auxiliary means for aiding in the conduction of heat away from'the refrigerant condenser is eliminated without sacrifie-- ing eciency of operation of the system.

Another object of my invention :is to provide,

a generator-absorber type of refrigerating system controlled in a manner such that irrespective of the heat load of the condenser of the sys em. the burner of the system will be extinguished or heat supplied` thereby decreased when substantially all of the refrigerant in the generatorabsorber4 has been evaporated, so as to provide an eflicient system and one which will be economical to operate.

Another object of my invention is to provide a refrigerating system of the above mentioned character in which the evaporator of the system is maintained at a desired low, substantially constant temperature and in which a generating cycle will not be started until substantially all of the refrigerant medium'in the evaporator has returned to the generator-absorber so as to provide an efficient system.

Another object of my invention is to automatically control the temperature of the evaporator of a generator-absorber refrigerating apparatus inl an elcient but inexpensive manner. Y

Another object of my invention is to provide a new and improved control for controlling thetemperature of theevaporator of a generatorabsorber type of refrigerating apparatus.

Another object of Amy invention is to provide a ynew and improved control of the` above mentionedv character responsive to the temperatureof both the evaporator and the generator-absorber to control the refrigerating system in an eicient manner.

The invention consists in the improved construction and combination ofk parts, to' be .more

fully described hereinafterand the novelty of which will be particularly pointed out and distinctly claimed.

In the accompanying drawings, to be taken as a part of this specification, I have fully and clear- 5 ly illustrated my invention, in which drawings- Figure 1 is a diagrammatic view of a generar tor-absorber refrigeratlng system embodying my invention;

Fig. 2 is a view shown partly in elevation and 10 partly in section of a control device for the system of Figl and embodying features of my invention;

Fig. 3 is a view of my control device with the cover removed to show the operating parts thereof;

Fig. 4 is a top plan View shown partly in elevation and partly in section of the control device, and taken along the line 4 4 of Fig. 3;

Fig. 5 is a view shown in section of certain structural details of the control device and taken along the line 5-5 of Fig. 4;

Fig. 6 is a view shown in section of the control device and taken along the line 6-6 of Fig.

Fig. 7 is a View in side elevation of a part of the device of Fig. 2 and looking from right to left thereof;

Fig. 8 is a view shown in section of structural details of the control device and taken along the line 8-8 of Fig. 7, and

Fig. 9 is a view showing a modified form of my generator-absorber unit.

Referring now to the drawings by characters `of reference and first to Fig. 1, the refrigerating system shown comprises in general a generator- .absorber unit or apparatus a refrigerant evap-f orator 2, a refrigerant receiver 3 and a refrigerant condenser Il. Any suitable refrigerant medium may be employed such as, for` example, a solution of ammonia and water. The generatorabsorber i may be of any suitable type and 4may include a refrigerant container or tank yii beneath which an oil burner l may be provided for heating the refrigerant in the tank or con-1 tainer 6. The container 6 is preferably provided with one or more vents iia for the escape to out- `side atmosphere of the products of combustion.

l to a condensing temperature to liquefy the refrigerant, and from the condenser t the liquid ammonia is delivered to the refrigerant receiver 3.

The refrigerant evaporator or heat exchanger 2 may be of any suitable type and may be disposed in an enclosed space to be cooled., such as a compartment of a heat insulated box or refrigerator cabinet (not shown). The evaporator 2 may have a header i3 communicatively connected to the receiver 3 by a supply conduit Iii, which conduit preferably opens into the header I3 through the top wall thereof, or thereinto at a point above the level of the liquid ammonia refrigerant in the header The header I3 is preferably encased in heat insulating material I A check valve I5 is provided in the horizontal portion H58 of the conduit 3 that connects the vertical vconduit portions 3 and ii leading respectively to the generator-absorber container t and the receiver 3 This check valve prevents back ow or return of refrigerant medium to the generator-absorber from the receiver 3 with the result that a pressure is maintained in the receiver, which pressure will cause the liquid refrigerant to flow from uthe receiver 3 up through the supply conduit ill into the evaporator header I3 during the absorption cycle of the refrigerating system whenthe pressure is reduced in the generator-absorber container t. Communicatively connecting the conduit l and the conduit portion ESB on the inlet side of valve I5, there is preferably a vertically extending conduit it for the purpose of equalizing the pressure in the system during the generating cycle, and in this conduit I6 there is provided a check valve Il for preventing now of refrigerant from conduit i6 to conduit 3 via conduit I6 during flow of refrigerant fromnreceiver 3 to evaporator 2. Communicatively connecting the header I3 and the generator-absorber conltainer 6 below the liquid level therein there is a conduit I8 through which the refrigerant vapor returns to the generator-absorber from the evaporator header during the absorption cycle of the system, and preferably this conduit i3 is connected into the header l3jthrough the top wall thereof or above the liquid ammonia refrigerant therein. The vapor return conduit I8 preferably extends downward from the evaporator 2, along oneside of the generator-absorber container 6 to a point adjacent theA bottom thereofand is then bent and has an upl acetone conduits providing extended heat transfer or cooling surfaces and also providing or defining a compartment below header I3 for receiving one or more ice trays (not shown) The end of one leg of each of the U-shaped conduits terminates at its upper end at and is secured in and to the bottom wall of the header I3 while each of the other conduit ends or legs preferably projects upwardly, as at 2I,'through an aperture in the bottom wall of and into the header, to a point above the highest attained level of the liquid ammonia refrigerant therein. Beneath and externally of the header I3, each of the upstanding conduit portions or legs, designated 2l, which terminate in the portions 2l has a surrounding wall or conduit 22 spaced from the conduit portions 2la to provide an annular evaporating chamber for receiving the liquid ammonia refrigerant. The conduits 22 have upper A open ends secured in and to the bottom wall of the evaporator header E3, and have their lower ends closed and sealed around legs 2te, as at 2d. Depending from the header i 3 there is preferably provided a water sump 25 the lower end of which may be disposed below the U-shaped conduits 2i! and thefupper end of which may project upwardly within the header I3 to a point adjacent the top thereof and above the highest attained liquid level. Communicatively connecting each of the conduit portion 2ia and the water sump 23, externally of and below the header i3, there is a horizontally extending conduit 2S for the passage of water from each of the conduit portions ZIB to the water sump 25. Extending downwardly within the water sump 25 to a point. adjacent the bottom thereof, as at 2te, there is one end of a Water return conduit 2l, the other end of which is preferably secured in and to the bottom wall of the generatorabsorber container 3, as at 2l?.

A conduit t@ has Lone end 3i communicatively connected to the generator-absorber container 3 and its other end communicatively connected to the upstanding conduit portion I9 of the vapor return conduit I3. The end 3i of the conduit 3@ is preferably secured in and to a side wall of container 6 at a pointislightly above the point of connection of the vapor return conduit portion I3. The other end of conduit 33 is preferably connected to the vapor return conduit portion i3 slightly above the bend or lowerrnost point of conduit IB. The conduit 30, conduit I3 and container 6 provide a circulatory system for aqueous refrigerant medium which circulates therethrough so that after the burner is extinguished, or during the absorption cycle of the system there is circulation for a purpose to be hereafter described in detail. 'The lconduit has a. horizontally disposed loop portion 32, and secured to and in thermal contact with the legs of portion 32 there is preferably a plurality of spaced plates or ns 33 providingex-` tended cooling surfaces for enhancing the conduction of heat away from the conduit loop portion 32. Enclosing the loop portion 32 there is a. easing or housing 34 of heat insulating material' having a top wall 3l!al provided with an opening 35 therethrough that is preferably controlled by a. light weight or substantially frictionless damper 36. 'I'he bottom of the housing 34 may be open', as shown, for the entrance of l air thereinto, and the rate at, which the air is" permitted to escape through the opening 35 to outside atmosphere, Vby the damper 36, determines the rate of cooling of the aqueous solution in the generator-absorber container 6 and determines the corresponding rate of evaporation of the refrigerant in the evaporator 2.

My control device, designated in general by the numerah31, controls operation of the. burner 1 in accordancey with the level of the aqueous solution in the generator-absorber I unless the temperature of the solution should increase beyond the predetermined temperature at which the control is set, in which event the burner would be shut off. The control device 31 also operates the damper 36 in accordance with the temperature of the evaporator 2 to maintain the temperature of the evaporator substantially constant`irrespective of change of heat load. The control device 31 may include a gravity feed fuel control having a casing 38 containing a chamber 39, see Fig. 2, in which fuel such as oil may be maintained at a substantially constant level by a float 40 operating a valve 4I controlling a fuel inlet port 42. The inlet port `42 may be connected by a supply conduit 43 to a reservoir tank (not shown) or to any other suitable source of fuel supply, and in the supply conduit 43 there is preferably provided a manually operable valve 43 for starting and stopping flow of fuel to the chamber 39. The constant level chamber 39 has an outlet 44, and connecting this outlet and the burner 1 there is provided a conduit 45 through which oil may flow by gravity from chamber 39 to the oil burner 1. i

Integral with the bottom wall of and disposed within chamber 39, there is preferably an upstanding tubular wall member 41 that overlies and communicates with the outlet 44. Adjacent the bottom Wall of casing 39 the tubular member 41 preferably has areduced bore portion 48 providingl an internal, upwardly facing port and seat 49. Positioned for vertical reciprocal movement in the tubular member 41, above port 49, there is a valve member preferably having at its lower en d a conical face 5| for cooperating with port 49 to control flow therethrough, and

consequently control flow of fuel to they burner 1.-

In the side wall of the tubular member 41 there is preferably provided a slot 52 through which oil may flow from the constant level chamber 39 into the tubular member 41 for flow through port 49 when the valve 50 is open or raised from its seat. When the valve 50 is seated. as shown in Fig. 2, flow of oil to the burner 1 will be discontinued and the burner will, of course, be extinguished. In order-to light the burner 1 automatically, a constantly burning pilot burner 53 may be provided and located adjacent the main burner 1. The pilot burner 53 may be connected to a suitable source of fuel supply by means of a conduit 53B in which there is preferably provided a manually operable valve 53h for opening and closing the conduit to flow therethrough. The valve member 50 has a stern 54 that extends unwardly within the constant level chamber 39 and projects through the top wall thereof, the said too wallbeing formed; in the present instance, by a re.

stem 54. 'I'he spring 58 is under compression actof fuel to the burner 1.

Mounted Aon the cover 55 and removable therewith as a unitary structure there is an actuating mechanism for actuating the valv/e 50 and for actuating the damper 36. The actuating mechanism has a casing 66 preferably of rectangular shape having a top wall 6I, bottom wall 62, side walls 63, 64' and end walls 65, 65E. In the present instance, the side wall 64 and the end walls 65, 65a are integral and are removable from the casing as a cover. Screws 66 may extend through apertures in the side wall 64 and thread into the opposite side wall 63 to hold the cover in place. In the bottom wall 62 of the casing 60 there is provided an aperture through which the upstanding tubular boss 51 of the casing cover 55 projects upwardly Within casingl slightly above the casing bottom wall 62. Disposed within the casing 60 there is a metallic supporting member 68 having a base 69 seating on the casi-ng bottom wall 62, the base 69 having an aperture therethrough for receiving the upstanding tubular boss 51 of casing cover 55. The tubular' boss 51 is externally threaded for receiving a nut 10 by means of which the cover 55,I casing 60 and supporting member 68 may be rigidly secured toso 64. Journaled for rotation in aligning aperturesin the flanges 1|, 12 there is a sha-ft 13, and surrounding the shaft 13 and extending between the flanges 1l, 12 there is preferablya tubular member 14 that may be secured to the shaft for rotation therewith by a pin 148, see Fig. 5. 'I'he tubular member 14 preferably has a substantially horizontally extending enlarged end portion or shank 15 disposed adjacent thel inner side of the upstanding flange 12, the enlarged portion 15 providing a vertical abutment face or shoulder 16 that faces inwardly or toward the flange 1|. Preferably the enlarged portion or shank 15 is of rectangular form and extends longitudinally of the casing 60, and this enlarged portion constitutes a lever by means of which the tubular member 14 and shaft 13 may be rotated. Carried by the rotatable tubular member 14 there is a. lever 11 that is to rotate with the tubular member to actuate the valve 50. The lever 11 may have an aperture therethrough adjacent one end for receiving the member 14, and may be positioned against the shoulder 16 of member 14 as shown. At the shoulder 16 the tubular member 14 may have an enlarged portion 16a which may be polysided, and the aperture in the lever 11 in which the said polysided portion positions may be of like shape so as to prevent relative movement between the tubular member 14 and the lever 11, or these parts may be connected for rotation together in any other suitable manner. The lever 11 extends longitudinally of the casing 60 toward the end wall thereof, and the free endof the lever preferably has a laterally and substantially horizontally extending flange 18 that overlies the upper end ofthe valve stem 54. Preferably a screw 191s adjustably screw threaded into the upper end of' the valve stem 54, longitudinally thereof, and extends above the upper end of the.

valve stem and is received in an aperture provided 4 in the lever flange 18. The screw l may have a head 80 positioned above the`upper surface of the lever ange 18, and below the screw head 80 the screw 19 may have a portion of reduced diameter 5 to provide opposed horizontal abutment surfaces f 82, 83 for abutment with opposite sides' of the lever 11. The opposed abutment surfaces 02, d3 are suitably spaced from each other so that on opening of the valve 50 the lever il will have a l desired, predetermined pivotal movement,` or lost motion, before the lever 1l will engage the upper abutment surface 82 andralse the valve 50 from its seat. j

Supported by the upturned supporting member 15 flanges 1|, 12 there are movable arms or levers 80, each lia-nge having one lever, these levers extending substantiallyparallel with each other toward'the casing end well 65, and longitudinally of and on opposite sides of the lever l1. Prefer- ,20 ably the levers 00 are attached to the anges li,

i2 by resilient hinge members 85 in a manner such that the levers are movable toward and away I from each other in planes substantially transverse to the plane of movement of the lever ll about 5% its fumrum. Rigidly secured to the lever 'n there 0. member 86 has recesses in opposite sides thereof providing sockets 87 that face one toward each 1 of the levers 84 which also have inwardly facing recesses providing sockets 0S adjacent their free ends. Connecting the lever 'Hl and the levers 0d there is a pair of movable thrust members or pins 89 that preferably have their opposite ends pointed for seating in the sockets d?, .00. A helical coil spring 90 is preferably provided ior urging the levers 84 toward each other, and'in so doing :uf acts through the'levers and the thrust pins 89 to pivot lever 11 in a counterclockwise direction, as seen in Fig. 3. When the valve 50 is seated, as shown in Fig. 2, the thrust pins 09 will be in alignment, or on so-called dead center, but when the ,45 lever` 11 is pivoted slightly in a counterclockwise direction L lift the abutment member 99, as seen in Fl 3, the pins 89 will be moved out of alignment permitting the spring 90 to pivot lever 11 with a snap action. Y

Mounted on the casing top wall Si there is a temperature responsive power element or actuator, designated in general-by the numeral 9|, that acts through the lever 11 to actuate the valve 50 in response to increase of temperature er 'element 9| may 'include'aasing 92 that is preferably mounted on the top wall of casing 60, externally thereof. The lower end oi' the power element casing 92 is open and preferably has an external rectangular ange 93 for seating on the casing top Wall 6|.v '.Ihe casing flange 93 may be provided with apertures at its corner portions for receiving screws 94 for rigidly securing the casings 92 and 60 together. A supporting member 95 in the form of a plate is secured and hermetically sealedto the inner side wall of casing 92 adjacent the lower or open end thereof. The supporting plate 95 extends transverse to the side wall of the casing 92 and is provided with a centrally disposed aperture therethrough. Disposed in the power element casing 92 there is a, tmetallic bellowsv 96 that cooperates with the casing 92 to provide an expansible chamber'91, and oneA end of the bellows 90 is ,1.75 securedrand hermetlcally sealed to a border porof the generator-absorber container 6.- The. powaraches tion of the supporting plate '95 around the aperture therethrough. The other or free upper end of the bellows 96 -is secured and hermetically sealed to a movable end wall or plate 91B that is disposed towardthe power element casing top wall, which top wall serves as a stop for hunting expansion movement of the bellows 96. 'I'he power element 9| includes a bulb element 98 that is preferably disposed within the generator-absorber container and communicatively connecting the bulb element 90 and the expansible chamber 97 there is a conduit or tube |00. The power element may be charged with any. suitable temperature responsive, expansiblecontractible fluid, such as for example butylalcohol. Preferably the bulb element 98 is enclosed or surrounded by a closed well or conduit |008, preferably iormedof metal and arranged in contact or in good heat transfer relation with the bulb element 98. The well of conduit |00a preferably projects into the container 6 through a sidewall thereof, and the conduit preferably extends horizontally and rests on or is arranged in good heat transfer relation with the crown sheet or top wall |00b of the combustion chamber forthe burner l.

Carried by the bellows movable end wall 91a there is a rod-like thrust member |0| that transmits compression movement of the bellows 90 to the lever 11. The thrust rod |0| extends centrally through the bellows 9G into the casing 00 through an aperture in the top wall 6| thereof, and adjacent its lower end the thrust rod Ais preferably received and guided in an aperture provided in a horizontally disposed ange portion ,|02 projecting from the supporting member vertical side ange l2. The flange portion |02 overlies the lever 'l1 and serves as a stop for engagement by the upper edge portion |02 of the lever to limit pivotal movement thereof in a clockwise direction, as seen in Fig. 6. At its lower Y end the thrust rod |0| is preferably pointed, as

at 03, for seating in an upwardly facing recess or socket |04 provided in the enlarged portion or lever of the rotatable tubular member 14 to which the lever vil is connected. The thrust member 0| is arranged to engage the enlarged portion 15 at *one side of the longitudinal axis of shaft 13 such that downward movement of the thrust 'member will rotate member 15 and lever 11 in a counter-clockwise direction, as seen in Fig. 6, which will result in the valve 50 being moved to closed position. At its free end the lever 11 has a downwardly directed, extended portion |05, the lower end of which is adapted to engage the upper surface of the supporting vmember base`69 to limit pivotal movement of the lever 11 in a. counterclockwise direction, as seen in Fig. 6.

Surrounding the thrust rod I0| there is preferably a helical coil spring |08 having one end, or its upper end abutting the bellows movable end wall 91* and its other, or lower end abutting a supporting member |01 that may be a. U- shaped bracket. The U-shaped bracket |01 may be rigidly .secured to and depend from the casing top wall 0|,'wlthin the casing, and may have a horizontally disposed portion |00 above flange |02, provided with an aperture vthrough which the thrust rod |0| may extend. The spring |06 is under compression exerting a force opposing closing of the valve 50 by the power element 9|, and the force exerted by this spring determines the temperature to which the generator-absorber bulb element must be heated bewise or valve opening direction,` as seen in Fig. 3;

subsiaiiiiaim in their deed 'center position se that fore the power element will act to extinguish the burner 1.

The tubular member 14 that rotates with the shaft 13 preferably has an externally threaded end portion for receiving an internally threaded tubular member or sleeve 0 that rotates with the tubular member. A pme-like lever member I|| is supported by the shaft 13 and is provided with an aperture adjacent one end thereof for receiving the tubular member H0, the lever I extending toward the casing end wall 65a, or in a direction opposite from the direction in which the lever 11 extends from shaft 13. A slip clutch II2 is provided and is adapted to couple lever III to the tubular member 14 when the lever III is pivoted in a counterclockand the slip clutch may include a pair of friction discs |I3 that may be formed of rubber or other material having a suitable coeilicient of friction. The friction discs II3 surround, or have centrally disposed apertures for receiving the tubular member IIO, and are positioned one on each side of and preferably have at surfacesA in abutment or engagement with opposite sides of the lever I I I.

Preferably the friction discs II3 are each provided With cup-shaped metallic retainers, one for each disc and designated respectively ||4 and |I5, of which the retainer |`|5 preferably has a circular shaped aperture for receiving the tubular member 14 and is preferably positioned flat against the lever 11. The retainer ||5 is tightly and frictionally held against the lever 11, for rotation therewith, by the tubular member ||0 which has one end abutting the retainer ||5 urging the retainer against the lever 11. The tubular member |I0 preferably has a square shank I I6, and threaded onto the tubular member 14 there is preferably a lock nut II1 that abuts the end of the shank IIS and prevents movement of the tubular member I I0 relative to the tubular member 14. The retainer II4 surrounds the square shank ||6 of member IIO and is provided,

with a centrally disposed rectangular aperture for receiving the shank so that the retainer ||4 will rotate with the shaft 13. Preferably a helical coil spring ||9 surrounds the shank |I9 of member ||0 and has one end abutting the lock nut ||1 and the other end abutting the retainer I|4, which retainer is adapted to move longitudinally of the tubular member I0. The spring ||9 is under compression and urges the :opposed faces of the friction discs I I3 against the opposite sides of the lever I I I to couple thleverto the shaft 13. In this construction the lever III is operable to exert a predetermined torque through the friction disks to the shaft 13 and will slip relative to the shaft by means of the friction disks II3 when that torque isexceeded. When the lever 11 is pivoted in either direction, the clutch ||2 will slip, due to the relatively great force necessary to move the power element. to be hereinafter described, so that pivotal movement vof the lever 11 will not be transmitted to the lever III. Also. if lever I|| is pivoted in a clockwise direction, as seen in Fig. 3, the clutch ||2 will slip to prevent movement of lever 11, due to the relatively great component of force exerted by the spring 90 urging the lever 11 in a counterclockwise direction, but when the lever is pivoted in a counterclockwise direction, the valve i0 being in closed position, the clutch will couple lever III to the shaft 13 so that lever 11 will be pivoted .to [open the valve 50 because the thrust pins 39 are responsive actuator or power element, designatedv i in general by the numeral |22, that is responsive to the temperature of the evaporator 2, or to the temperature of the ammonia refrigerant therein. The power-element |22 may be and preferably is constructed in the same manner as the hereinbefore described power element 9|, and therefore a detailed description of the power element |22 is deemed to be unnecessary. y Preferably the power element |22 is larger than the` power element 9 I, or is constructed so that it will exert a greater force than the power element 9|. The power element |22 comprises in general a casing or container |23, a bulb element |24 connected by a tube or conduit |25. Secured to and disposed within the casing |23 there is a metallic bellows |26 that cooperates `with the casing to provide therewithin an expansible pressure chamber |21 that is communicatively connected to the bulb element |24 by the conduit |25. The power element |22 may be charged with any suitable temperature responsive, expansible-contractible fluid, for example iso-butane. Preferably the powery element bulb |24 projects into the evaporator 2 and is disposed above the liquid level therein so that the bulb will be subjected to the temperature of the vaporous ammonia therein. The power element casing |23 may be mounted on the upper surface of the top wall 6I of ,cas-

ing 60, alongside of the smaller power element 9|, and preferably substantially overlying the free end of the lever III. The bellows |26 has a movable end wall |23, and carried thereby there is preferably a thrust rod |29 for transmitting movement of the bellows |26 to the lever III. The thrust rod |29 extends centrally through the bellows |29 into the casing 60, through an aperture in the top wall 5| thereof. and downwardly within the casing 60, and projects externally of the casing through an aperture in the casing bottom wall 92. Externally of the casing 60 the thrust rod |29 is connected adjacent its lower end to one end of a lever |30 that may be'pivotally supported by the heat insulating housing 34, the other end of the lever |30 being pivotally connected to the damper 36 by a link |3|. The

power element thrust rod |29 is connected to the damper 36 in a manner such that when the thrust rod is moved downward the damper is moved toward open position. Opening of the damper 38 increases air circulation through the housing 34 y v Within the casing il the power element thrust l rod |29 has a portion of reduced diameter, as at 3 providing spaced, opposed, substantially paralle! and horizontal shoulders or abutment surfaces |32. Rigidly secured to the lever :ad- 5 jacent its free end there is a laterally extending abutment member, preferably a pin |33 that positions between the abutment shoulders |32 for cooperation. therewith to pivot the lever lll. The abutment surfaces |32 are spaced a distance apart such that there wllbe a predetermined lost motion between the rod |29 and the lever so that the power element |22 can operate the damper 36 within a desired operating range Without pivoting lever Surrounding the power element thrust rod |29 within the casing 60 there is preferably an open ended tubular memf ber |34 that may seat on the casing bottom wall 62. The tubular member |34 may be rigidly secured to the casing bottom wall 62 by a second open ended tubular member |35 that may be inserted in member |34 and receive and guide the thrust rod |29. The insert tubular member' |35 may have external annular anges |36 at its opposite ends, one of which flanges may hold 'spring ngers, to be hereinafter described, against the upper surface of the member |34 and the other of which may abut the underside of the casing bottom wall 62. A plurality of upturned spring lingers I 31 are provided for frictionally 60 engaging the thrust rod |29 to dampen vibration thereof. The spring fingers |31 may be integral and formed out of a piece of spring metal that may have a centrally disposed aperture for .receiving the insert member |35, and may vseat on 35 the upper end of member |34 and be held thereagainst by the upper ange of insert member |35. At their upper ends the spring. fingers |31 are preferably bent or rounded, as at |38, so as to have convex surfaces for engaging the thrust f o rod |29 to provide a smooth bearing surface on each of the lingers. Surrounding the spring fingers |31 and positioned in the indented or concave portions formed by the bent or rounded upper ends, there is preferably a coil spring |40 under tension urging the spring ngers |31 inwardly toward and holding the ngers against the rodY |29 to increase the friction on the rod |29. A low'er end portion of the rod |29 is preferably of reduced diameter, as at |4|, providing 5g a downwardly facing, external annular shoulder |42. Adjacent its lower end the tubular insert member |35 has a bore portion |43 of reduced diameter for receiving the reduced rod portion |4l., and providing an upwardly facing internal' AVgg; shoulder |44 for abutment by the rod shoulder |42 to limit downward movement of the thrust rod |26.

Surrounding the thrust rod |29 there is a helical coil spring |45 that has one, or its upper end 30 abutting the bellows movable end wall |28 and its other, or lower end abutting a movably ad.

instable supporting member |46. By changing the position of or moving the supporting member |46, the magnitude of the spring force may 65 be changed to determine or regulate the tem- V perature at which the power element |22 will overcome spring |45 and open the valve 50. Pivotally supported within -the casting 60 there is an adjustment lever |41 that supports thev flanges |48 may project into the casing 66, and the flanges |43 may have aligned aperturesfor receiving a shaft |49 for pivotally supporting the adjustment lever |41. The lugs |46 may be formed out of a plate |56 that preferably lies at against the outer surface of the casing side wall 63. The adjustment lever 41 preferably has a pair of spaced, substantially parallel lever arms |5| between which the movable abutment or supporting member |46 positions, the member |46 preferably being a cup-shaped member having an upper open end provided with an outturned annular flange |52. Adjacent their ends, the lever arms |5| preferably have upwardly directed extended portions |54 that are preferably pointed at their upper ends for engaging in downwardly facing, oppositely disposed recesses or sockets formed in the outturned flange |52 of the adjustable supporting member |46.

Carried by the casing side Wall 63 there is a manually operable adjustment mechanism for pivoting the adjustment lever |41 to change the force exerted by the spring |45. The casing side wall 63 is preferably provided with an aperture through which a fitting or tubular member |55 extends into the casing 66, the fitting |55 preferably being internally threaded for adjustably receiving an externally threaded adjustment member |56. The fitting |55 also extends through an aperture provided in the plate |50, out of which the shaft supporting lugs |46 are formed, and' extends through an aperture in a dial plate |51. The fitting |55 preferably has a head |58`externally of the casing 66, and thedial plate 51 is disposed between the head |58 and plate |56. An inner end portion of the tting |55 may be peened over, as shown, to rigidly secure the fitting, plate |56 and dial plate |51 to the casing rear wall 63. The adjustment member |56 has a centrally disposed, longitudinally extending bore |60 that opens through the inner end thereof and this bore slidably receives and guides a thrust member, preferably a pin 6|. The opposite ends of the pin |6| are preferably rounded, as shown, and the inner end of the pin engages or -abuts a connecting or cross member |62 that is integral with and joins the lever arms |5| of the lever |41, the pin-|6|- preferably. engaging the cross member |62 at a point below thelongitudinal axis of the shaft |49'and at a point nsubstantially midway between the lever arms 5|.

The adjustment member 5|56 has an enlarged bore portion |63 that opens through its outer end, and the bore |63 is ,preferably internally threaded for receiving a manually operable adjustment screw |64 for adjusting the position of the abutment pin |6| with respect to the adjustment member |56. A handle |65 for conveniently rotatingthe member |56 may be se"- cured to the. outer end thereof by means of a screw |66 that may be screw threaded into bore |63. 'Ihe handle |65 may have its outer end pointed, as at |61, Fig. 7, to serve as a pointer for cooperation with indicia (not shown) on the dial plate |51 to aid in accurately setting the device. When the thrust member |55 is rotated in -a directionsuch that Vit is m'oved inwardly and pivots adjustment lever |41 in a clockwise direction, facing Fig. 2, then the force exerted by spring |45 will be increased with the result that the powerA element |22 will open valve 56 at a higher refrigerant temperature.

'Ihe operation of the herein described refrigerating system and controls therefor is as follows: To start the system the manually ,operable valve 53b controlling flow of fuel to the pilot burner 53 is opened, after which the pilot burner may be lighted. 'Ihe manually operable valve 43a controlling ow of fuel to the fuel reservoir or constant level chamber 39 is then opened and by means of the manually operable lever |20 the outlet vlave 50 may be moved to open position to permit now of fuel to the main burner 1 Vwhich -is then ignited by the pilot burner 53. The

` crown sheet.

valve 50 can be moved to open position by the manually operable lever |20 because when the temperature of the aqueous solution in the'container 6 is below -a predetermined temperature, or at room temperature, the thrust rod |0| of the power element 9| will be in a retracted position out of engagement with the lever 11. The parts of the control device will be in the positions shown at the time of completion of a generating cycle of the system. With the lighting of the main burner 1, the generating cycle of the system begins as the burner heats the aqueous solution in the generator-absorber container 6. Heating of the aqueous solution in the container 6 drives out the ammonia in a vaporous state along with some water Vapor and the vapor ows up conduit 9 to the condenser I0 where the major portion of entrained water vapor is condensed and returned by gravity to the container 6, the ammonia vapor and the remaining water vapor continuing to the condenser 4 where it vis condensed and from whence it flows down through conduit I into the receiver 3. As the vaporflows en route to the condenser 4, some of the vapor will pass the check valve I 1 and flow through the conduit I6 into the supply conduit I4 to create a pressure in the evaporator for a purpose to be hereafter described. The power element 9|, responsive to the temperature of the generator-absorber I, is set so that it will not close the valve 50 to extinguish the burner 1 at the temperature to which the aqueous solution is normally heated by the burner. During the generating cycle, as liquid ammonia continues to be delivered to the receiver 3 from the generator 6, the level of the aqueous solution in the generatar-absorber container 6 will of course decrease, but so long as the liquid level is at a height such that the liquid wets the bulb well |00, the fluid in the bulb 'will remain at the same temperature as the aqueous solution, with the result that the power element 9| will not act to extinguish the. burner 1. However, shortly after the aqueous! solution level decreases to a level, as at L-L, below the bulb well |00a thus exposing a portion of the crown sheet |00", the temperature of the, bulb and fluid therein will-be quickly increased by the heat of the burner llame impinging' on the As the temperature of the fluid in the bulb 98 reaches -a predetermined temperature, the fluid pressure will have compressed the power element spring |06 and have moved lever 11 against the force of spring 90, pivoting the lever 11 in a counterclockwise direction, facing Fig. 6. Since the resistance of spring 90 decreases upon` movement of lever 11, the force of power element 9|, which will start lever movement, will complete the movement of the valve with a quick or snap action to closed position. When the 1ever 11 is pivoted as above mentioned, the slip clutch ||2 will slip due to the resistance of power element |22 so that pivotal movement of the lever 11 will not' be transmitted through the lever III. Pivotal movement of lever 11 in a counterclockwise direction will permit the valve 50 tol descend quickly by gravity, aided by the spring 58 which urges the valve against its seat 49 and closes the`outlet port. Closing of the valve 50 will, of

course, vstop fiow of fuel to the burner [which ature at which the power element 9| is set to operate. As the weak aqueous solution in the container 6 cools, the absorption cycle begins and cooling of the solution is accomplished by decrease in the pressure in container 6 and accompanying decrease in the pressure in the evaporator 2, which causes liquidvammonia refrigerant to flow froml the receiver 3 up through the conduit I4 into the evaporator 2.

When all of the liquid ammonia in the receiver 3 has been delivered to the evaporator 2, the evaporator will be substantially illed. The cooling of the evaporator now begins, the liquid ammonia in the evaporator 2 evaporating and cooling; or lowering the temperature of the evaporator and thereby the space or compartment in which the evaporator may be located. As the liquid ammonia evaporates in the evaporator 2, the ammonia 'gas or vapor returns to the generator-absorber I via the conduit I8 and is absorbed by the water in conduit member I9 and or aided by chemically generated heat evolved when the returning, almost pure ammonia 'vapor dissolves in the weak aqueous solution at the connection of the loop portion 32 and the upstanding vapor return conduit portion I9. The conduit portion 32, and therefore the aqueous solution circulating therethrough, is cooled by air which enters the housing 34 through the bottom thereof, the rate of cooling being determined by the rate of air ilow over radiating portion 32 under control of the damper 36. The rate of` absorption by the water of the ammonia vapor returning to the generator-absorber I, and therefore the rate of evaporation of the liquid ammonia in, or the rate of cooling of the evaporator, depend upon the rate at which heat is conducted away from the conduit loop portion 32 in the housing 34. y

Before the absorption cycle starts, the evaporator header portion I3 will be warm with the result that the bellows |26 of the power element |22 will be compressed by the expansiblecontractible fluid of the powerv element-, When the bellows |26 is thus compressed, the thrust or connecting rod |29 will be held in its down position against its stop |44, and the damper 36 will be held in an open position such as will permit a desired, rapid absorption of. the am-` monia vapor by the aqueous solution in the evaporator 2. As the evaporator 2 cools, the expansible-contractible fluid in bulb |24 of the power element |22 will correspondingly contract permitting the spring |45 to compressthe bellows |26 which will move the connecting rod 29 upward. Upward movement of the connecting rod |23 will pivotl lever |30 in a clockwise direction, as seen in Fig. 1, and will move the damper 36 toward closed position. Movement of thedamper 36 toward closed position will restrict the air circulation over the-conduit portion 32 thereby decreasing its radiation and the rate of absorption, by the aqueous solution from the container 6 of the returning vapor in conduitl i8, with accompanying decrease in the rate of evaporation of the ammonia inthe evaporator 2 as the evaporator approaches the desired temperature. Upon predetermined upward movement of .the bellows thrust rod |29 the lower or upwardly facing abutment surface |32 thereof will engage the lever pin it, and predetermined further upwardmovement of the thrust rod |29 will move lever to its up position preparatory to movement of lever downward to start a generating cycle. The aqueous solution in the generator-absorber will also cool, causingV the bellows 96 of the power element 2li to contract under force of the spring |06 and to move the thrust rod |li| upward out of engagement with the abutment member or lever 'l5 of lever il so Athat lever 'Il can be moved upward without opposition for starting a generating cycle. When the evaporator 2 has been cooled to a predetermined desired temperature, determined by the force exerted by the power element spring |45, the power element |22 will have operated the damper 36 to full closed position at which normal heat leakages at the evaporator and from casing 34 will be substantially balanced so as to maintain the desired evaporator temperature substantially constant. For example, if for any reason the heat load on the evaporator 2 is increased, the power element |22 will accordingly move the damper 36 in an opening direction and increase the rate of evaporation of the ammonia refrigerant in the evaporator 2 to therel by compensate for the increase in heat load. r

in other words, for all changes of the heat load on the evaporator 2, the position of the damper 36 will be accordingly and automatically changed or throttled by the power element |22 to correspondingly change the rate of evaporation of the ammonia refrigerant in the evaporator and thereby maintain the evaporator temperature substantially constant. Below a predetermined evaporator temperature after lever has been reset as above noted; the power element |22 will actuate the damper '36 without acting on the lever I because of the lost motion connection therebetween provided by the spaced abutment shoulders |32 of the rod |29 and the pin |33 of lever ||I. As the quantity of ammonial refrigerant in the evaporator 2 decreases, the damper 36 is correspondingly moved toward, open position to increase'the rate of evaporation of the ammoniav to thereby maintain the evaporator temperature substantially constant, When substantially all of the ammonia in the evaporator 2 has been used, orhas evaporated, the temperature of the evaporator, and consequently the temperature of the power element bulb |24, will.

increase whichwill cause the power element Vthrust rod |23 to be moved downward. After the thrust rod |29 has been moved downward a predetermined distance its downwardly facing abutment shoulder |32 will engage the abutment pin |33 of lever and continued downward movement of the thrust rod will pivot lever I ina clockwise direction, facing Fig. 6. When the power element |22, on heating up of the evaporator 2, pivots lever in a clockwise direction, facing Fig. 6, the friction slip clutch ||2 will hold or couple the lever to the shaft 13 with the result that the lever will be pivoted in a clockwise direction. Slight pivotal movement of the lever ina clockwise direction, facing Fig. 6, will move the thrust pins 83 from their dead center positions which will permit the spring 90, acting through the hinge members 8d and pins 89, to pivot the lever with a snap action. After predetermined initial pivotal movement of the lever` 'il by the spring 90 the under surface 82 of the valvei screw head 80 will be engaged by the lever which -will then carry the valve upward away from its seat d@ with a snap action. The lost motion connection between the lever 'il and the valve 50 is provided so that the lever will be in motion before it takes up the additional load of lifting the valve 50. The valve 50 is now open and fuel will again flow to the main burner 'l which will .be automatically lighted by the constantly burning-pilot light 53 to again start the generating cycle.

From the above description it will now be seen that the power element 9| permits the burner 'l to heat the solution in the container 6 until a predetermined substantially constant quantity of the ammonia has been driven off, after which the power element 9| will extinguish the burner.

` It will also be seen that the other power element |22 permits the) burner l to remain extinguished until substantially all of the ammonia refrigerant has been used in cooling and maintaining the evaporator cool. Element |22 also actuates the damper 35 to obtain a given temperature vin the evaporator by a proper or desired rate of evaporation of the ammonia in the evaporator which is obtained by controlling the rate of absorption of the gaseous ammonia by the water in the4 container 6. 'I'his resultskin an -emcient system since substantially all -of the ammonia is utilized each cycle thereby maintaining the evaporator at maximum capacity due to its flooded i condition, and the rate at which the refrigerant iis absorbed is controlled in accordance with the desired temperature of the evaporator tomaintain the evaporator at a desired, substantially A constant temperature during the absorption part of the cycle.

. Asis well known, the capacity of a condenser depends upon the difference in temperature between the fluid to be cooled and the cooling fluid f be heated by the burner via the metallic container with the result that the bulb will be quickly heated to the temperature at which the power element 9| extinguishes the burner. By this arrangement it will be seen that the burner 'I will not remain lighted am' longer than necessary to drive out substantially all of 'the ammonia from the aqueous solution regardlessof the liquid temperature, which of course provides for economical operation of the burner. In the summer time when the condenser has less capacity the burner will remain lighted for a correspondingly longer period in order for the ammonia to be driven from the liquid in the generator or until the temperature of the aqueous solution reaches the pre- 5 determined temperature at which the power element acts to extinguish the burner, or until the liquid level in container 6 decreases below the bulb 98. 'Ihus it will be appreciated that the 4 operating temperature of the power element 9| l need not be reset or changed for condensers of dierent capacities, nor need it b e reset upon the occurrence of seasonal changesl affecting the capacity of the condenser in order to have a predetermined minimum quantity of ammonia remain in the liquid in the generator which insures an ample supply of liquid ammonia to the evaporator every cycle. This is of course advantageous.

The rectifier or condenser I0 will not remove all of the water from the ammonia vapor with 20 the result that after completion of an absorption cycle of the system there will be some water left in the evaporator 2 which was carried there in solution by the liquid ammonia through conduit Hand by the ammonia vapor through conduit 25 I6. However, the Water-ammonia solution rich in water left in the evaporator 'at the end of each absorption cycle is returned to the generatorabsorber l each succeeding absorption cycle in the following manner: When liquid ammonia is 30 again supplied to the evaporator 2, the ammonia will by its own weight push the solution 4rich in water through the evaporator conduit 20, Zia up to and through the conduit 26 into the water sump 25. During the succeeding generating cycle the pressure of the ammonia vapor transmitted to the evaporator 2, via conduit I6. will act through passageway 26 on the water in sump 25 to force it upward and through conduit 21 to the generator-absorber container 6.

40 Referring now to Fig. 9 of the drawings, in this view there is shown a refrigerating system that is similar to the system of Fig. 1 and therefore like parts of the two systems aredesignated by like numerals. 'I'he system of Fig. 9 differs 4'5 from that of Fig. 1 in the construction of the generator-absorber in that the container 6 is substantially entirely enclosed by heat insulating material |68 instead of having a housed conduit portion for circulation of the aqueous solution as 50 in the system of Fig. 1. In the insulation |66 below the container 6, there is provided an opening |69 for the entrance of air which may ow out through thevents 6 to conduct heat away from the container 6 thereby to cool the aqueous 55 solution therein. A damper |10 controls'ow oi'- air through the opening |69 to control cooling oi' the aqueous solution, and is actuated by the power element |22 inaccordance with the temperature of the evaporator and' thereby maintains 60 the evaporator temperature substantially constant. The system shown in Fig. 9 operates in the same manner as the hereinbefore described system shown in Fig. 1. What I claim and desire to secure by 'Letters 6i Patent of the United States is:

1. Refrigerating apparatus comprisinga generator-absorber for a liquid solution including a refrigerant medium, a refrigerant revaporator communicatively connected to said generator- 70 absorber so that refrigerant may pass therebetween. the level of the liquid solution in said generator-absorber rising and falling in accordance with the quantity of the refrigerant medium, in said generator-absorber, meansV for heating the 75 solution in said generator-absorber to vaporize the refrigerant medium and thereby lower the level of the liquid solution to a predeterminedA low level, means for condensing the vaporous refrigerant medium for supply vto said evaporator, normally acting temperature responsive means 5 directly heated by said heating means and operable at a predetermined temperature for decreasing the heat input by said heating means to the solution, said responsive means being so positioned and arranged relative to the solution level 10 that said responsive means is cooled by the solution to a temperature below said predetermined temperature solely at solution levels above said predetermined low level, said responsive means being operable upon decrease of the solution level l5 to said predetermined low level to be heated by said responsive means to said predetermined temperature, thereby to insure the reduction of solution level to said predetermined level prior to decrease of the heat input by said heating means to the solution, control means operable for controlling the rate of cooling of the solution to control the rate of absorption by the solution in the generator-absorber of the refrigerant evaporating in said evaporator. and means responsive to the temperature of said evaporator to actuate said control means to maintain the evaporator at a desired substantially constant temperature.

2. Refrigerating apparatus comprising a generator-absorber for a liquid solution including a refrigerant medium, a refrigerant evaporator communicatively connected to said generatorabsorber, means for heating the solution in said generator-absorber to vaporize the refrigerant medium, means for condensing the vaporous refrigerant medium for supply to said evaporator, temperature responsive means heated by said heating means and operable at a predetermined temperature to decrease the heat input by said heating means to the solution to initiate an ab- 40 sorption cycle, control means operable to control the rate of cooling of the solution and the corresponding rate of absorption by the solution in said generator-absorber of the refrigerant medium evaporating in said evaporator, and means responsive to the temperature of the evaporator for actuating said control means to maintain the temperature of the evaporator substantially constant, said last-named means also being operable on predetermined increase in the temperature of said evaporator to increase the heat input by said heating means to the solution to initiate a generating cycle.

3. Refrigerating apparatus comprising. a container for a liquid solution including a refrigerant medium, a refrigerant evaporator, supply and return conduits connecting said container and said evaporator, means for heating the solution in said container to vaporize the 'refrigerant medium, means for condensingthe vaporized refrigerant medium for supply to the evaporator, control means operable for controlling said heating means, means responsive to the temperature of the solution for actuating said control means, said responsive means being op-y 65 arable at a predetermined temperature to decrease the heat input by said heating means to `the solution to initiate an absorption cycleI conlast-named responsive means having a lost-motion connection with said first-named controlling means and operable upon predetermined increase in the evaporator temperature for actuating said first-named controlling means to increase the heat input by said heating means to the solution to initiate a generating cycle.

4. Refrigerating apparatus comprising a heat insulated container for a liquid solution including a refrigerant medium vand including insulated top and bottom walls, a refrigerant evaporator communicatively connected to said. container, means for heating the solution in said container to evaporate the refrigerant medium, means for condensing the vaporous refrigerant medium for supply to said evaporator, temperature responsive means heated by said heating means and operable at a predetermined temperature to decrease the heat input by said heating means to the solution to initiate an absorption cycle, said top wall being ported for flow of egress air, said bottom wall having an opening through its insulation for the entrance of air to cool the solution and for outflow through said top wall, a damper controlling said opening to control the rate of cooling of the solution and thereby control the rate of absorption by the solution of the refrigerant medium returning from said evaporator to said container, and temperature responsive means responsive to the temperature of the evaporator to actuate said damper to maintain said evaporator at a predetermined substantially constant temperature, said last-named means being operable upon a predetermined increase in temperature to actuate said heating means.

5. Refrigerating apparatus comprising a metallic container lfor a liquid solution including a refrigerant medium, a horizontally extending conduit system having its ends communicatively connected to said container at different levels below the minimum level of said solution in said container so that gravity circulation of said solution will occur, a refrigerant evaporator communicatively connected to said container, means for heating the solution in said container to vaporize the refrigerant medium, means for condensing the vaporous refrigerant medium for supply to said evaporator, temperature responsive means heated by said heating means and voperable at a predetermined temperature for decreasing the heat input of said heating means to the solution, heat insulating material enclosing at least a portion of said conduit system and having an opening therethrough .for air to conduct heat away from the portion of said solution in said system, a damper for said opening and operable to control the rate of heat conduction away from said solution portion whereby to control the rate of absorption by said solution of the refrigerant medium in the evaporator, and` means responsive to the temperature of said evaporator to actuate said damper to maintain a predetermined desired evaporator temperature.

, 6. Refrigerating apparatus comprising a metallic container for a liquid solution including a refrigerant medium, a refrigerant evaporator communicatively connected to said container, means for heating the solution in said container to vaporize the refrigerant medium, means for condensing the vaporous refrigerant medium for supply to said evaporator, control means for said heating means, an actuator for actuatingsaid control means to decrease the heat input of said heating means to the solution. said actuator including a temperature responsive element disposed, in the solution in said container and in good heat conductive relation with said container, said actuator being operable when the solution reaches a predetermined high temperature and also being operable when the liquid level of the solution decreases to a level such that said responsive element responds to the relatively higher temperature of said container above said level, means for controlling the rate of absorption by the solution of the refrigerant medium in the evaporator to thereby control the rate of evaporation of the refrigerant medium, and means responsive to the temperature of the evaporator for actuating said last-named controlling means to maintain a desired evaporator temperature, said last-named responsive means also being operable on predetermined increase in the temperature of said evaporator'to increase the heat input of said heating means to the solution.

7. Refrigerating apparatus comprising a generator-absorber for a refrigerant lmedium and including apliquid absorbing solution, means for heating the refrigerant medium and the solution in the generator-absorber to drive oi the medium until the solution level in the generator-absorber is reduced to a predetermined level, a refrigerant evaporator, a supply of conduit connecting said evaporator and said generator-absorber, a refrigerant return conduit connecting said evaporator and said generator-absorber, means operable for controlling said heating means, means directly heated by said heating means for normally actuating said controlling means said directly heated means being so positioned relative to said predetermined level that prior to the reduction of the solution level to said predetermined level said heated means is cooled by thesolution and subsequent to the reduction of level to said predetermined level the solution is ineffective to cool said heated means, and means responsive to the temperature of said evaporator for actuating said controlling means.

8. Refrigerating apparatus comprising a generator-absorber for a refrigerant medium, means for heating the refrigerant in said generatorabsorber, a refrigerant evaporator, a refrigerant supply conduit connecting said generator-absorber and said evaporator, a refrigerant return conduit connecting said generator-absorber and said evaporator, means operable for controlling said heating means, means-responsive to the temperature `of said generator-absorber for actuating said controlling means, means responsive t0 the temperature of said evaporator for actuating said controlling means, and means operable for controlling the rate of evaporation of the refrigerant in said evaporator and actuated by one of said actuating means.

9. Refrigerating apparatus comprising a `generator-absorber for a refrigerant medium, a refrigerant evaporator, supply and return conduits operatively connecting said evaporator and said generator-absorber, conduit means communicatively connected to said generator-absorber and cooperating therewith to provide a circulatory system for the circulation of the refrigerant medium during the absorbing cycle, a housing en- I closing a portion .of said last-named conduit means and having an opening for the entrance of air to cool the refrigerant medium circulating through said portion, a damper controlling said opening and operable to regulate the rate of cooling of the refrigerant medium circulating through said conduit portion, means for heating the refrigerant medium in said generator-absorber, means for controlling said heating means, means responsive to the temperature of said generator-absorber for actuating said controlling means, means responsive to the temperature of ,said evaporator for actuating said controlling means, said damper being actuated by one of said temperature responsive means.

10. Refrigerating apparatus comprising a generator-absorber for a refrigerant medium, a condenser, a refrigerant evaporator, conduit means connecting said generator-absorber and said condenser, conduit means connecting said condenser and said evaporator, return conduit means connecting said evaporator and said generatorabsorber, heating means for said generatorabsorber to heat the refrigerant medium, control means for controlling said heating means, means responsive to the temperature of said generatorabsorber for actuating said control means, means responsive to the temperature of said evaporator for actuating said control means, conduit means connected to said generator-absorber and to said return conduit means and cooperating with said generator-absorber and a portion of said lastnamed conduit means to provide a closed system for circulation of the refrigerant medium in the generator-absorber during the absorbing cycle, the refrigerant medium circulating through said circulatory systemlbeing cooled by air, means for controlling the rate of cooling of the refrigerant medium circulating through said circulatory system and actuated by one of said responsive means.

11. Refrigerating apparatus comprising a generator-absorber for a liquid solution including a refrigerant medium, a refrigerant evaporator communicatively connected to said generatorabsorber, means including heating means for separating the refrigerant medium from the solution for delivery to said evaporator, means including a temperature responsive element for controlling said heating means, said temperature responsive element being submerged in the liquid solution when the level of the liquid in said generator-absorber is above a predetermined level, said controlling means being operable to control' said heating means to reduce the heat inputy to the solution in the generator-absorber when the level of the solution decreases to a predetermined level below said temperature responsive means.

12. Refrigerating apparatus comprising a generator-absorber for a liquid solution including a refrigerant medium, a refrigerant evaporator communicatively'connected to said generatorabsorber, means including heating means for separating the refrigerant medium from the solution for delivery to said evaporator, means including a temperature responsive element for controlling said heating means, said temperature responsive element being submerged in the liquid solution when the level of the liquid in said generator-absorber is above a predetermined level, said controlling means being operable to control said heating means to reduce theheat input to the solution in the generator-absorber when the level of the solution decreases to a predetermined level below said temperature responsive means, means cooperable with said generatorabsorber to provide a circulatory system for the solution 'in said generator-absorber, means responsive to the temperature of said evaporator for controlling-said heating means and operable to control the rate of heat conduction away from the liquid circulating through said circulatory system to control the rate of absorption of the refrigerant medium by the solution to maintain ,a substantially constant evaporator temperature.

13. Refrigerating apparatus comprising a generator-absorber for a liquid solution including a refrigerant medium, a refrigerant evaporator communicatively connected to said generatorabsorber, means including heating means forv 'conduit means cooperable with said generatorabsorber Vto provide a circulatory system for the liquid solution in said generator-absorber, a housing enclosing a portion of said conduit means and having an opening for the entrance of air to -conduct heat away from said conduit portion, a

damper controlling said opening to control the rate of heat conduction away from said conduit portion, and means responsive to the temperature of said evaporator for regulating the position of said damper.

14. In a cntrol device, a controlling means, al

lever operatively connected to said controlling means, a power element operable to pivot said lever to move said controlling means in one direction, a second power element operable to pivot said lever to move said controlling means in an opposite direction, a slip clutch operatively connecting said second-named power element and said controlling means, and manually operable means for actuating said controlling means.

15. In a control device, a supporting means, a controlling means, a second controlling means, a lever pivotally supported byr said supporting means and operatively connected to said firstnamed controlling means, a power element operable to pivot said lever to move said rstnamed controlling means in one direction, a second lever pivotally supported bysaid supporting means and operatively connected to said secondnamed controlling means, a' power element operatively connected to and for actuating said second-named lever and operatively connected to and for actuating said second-named controlling means, and a slip clutch -operatively connecting said first-named lever and said second-named lever, said second-named power element being able to pivot said lever to move said rst-named controlling meanscin one direction, a second lever pivotally supported by said supporting means and operatively connected to said second-named controlling means, a power element operatively consaid first-named lever' nected to and for actuating said second-named lever and operatively connected to for actuating said second-named controlling means, and a slip clutch operatively connecting said` first-named lever and said second-named lever, said secondnamed power element being operable to actuate said first-named lever through said slip clutch to move said rst-named controlling means in the opposite direction, said second-named power element and said second-named lever having :a lostmotion connection therebetween.

17. In a control device, a supporting means, a controlling means, a second controlling means, a lever pivotally supported by said supporting means and operatively connected to said rstnamed controlling means, a power element operable to pivot said lever to move said rst-named controlling means in one direction, a second lever pivotally supported by said supporting means and operatively connected to said second-named controlling means, a power element operatively connected to and for actuating said secondnamed lever and operatively connected to for actuating said second-named controlling means, a slip clutchv operatively connecting said rstnamed lever and said second-named lever, said second-named power element being operable to actuate said first-named lever through said slip clutch to move said first-named controlling means in the opposite direction, said secondnamed power element and said second-named lever having a lost-motion connection therebetween, and snap acting mechanism for transmitting movement of said first-named lever to said first-named controlling means.

18. In a control device, the combination with a movable controlling means and a pair of power elements for actuating the controlling means, of a slip clutch for operatively connecting one of said power elements to the controlling means and of a rigid mechanical connection for the other of said power elements to the controlling means.

19. In a refrigerating system of the absorption type, a container for a liquid solution including a refrigerant medium, heating means for heating the solution to vaporize the refrigerant medium, and a control device for normally controlling said heating means, said control device including a temperature responsive element arranged to be heated by said heating means, said control device having a rst and a second position and being operable to move from said first to said second position when said element is heated to a predetermined temperature to decrease the heat input by the heating means to the solution said device being operable upon decrease in Atemperature below said predetermined temperature to automatically .move to said rst position, said element being arranged in het transfer relation with and maintained by the solution at a temperature below said predetermined temperature when the level of the solution is above a predetermined normal level, said element being heated to a temperature above the temperature of the solution by said heating means When the level of the solution is below said predetermined level.

20. A refrigerating apparatus comprising a generator-absorber, a condenser land an evaporator communicatively connected in operative relation, means to heat said generator-absorber, means for controlling ilow in heat exchange relation to said generator-absorber of a heat abstracting medium, means controlling the heat supplied by said heating means, means controlling said flow-controlling means, means operable upon occurrence of a predetermined low liquid level in said generator-absorber to actuate said heat controlling means to decrease the heat supply, means responsive to the temperature of said evaporator and acting through said last-named means to actuate said heat controlling means to increase the heat supply, means operatively connecting said temperature responsive means to said ilowcontrolling means to regulate cooling of said generator-absorber, and lost-motion means operatively connecting said temperature responsive means to said heat controlling means so .that said temperature responsive means will be ineffective to actuate said heat controlling means to decrease the supply of heat to said generator-absorber.

21. A refrigerating apparatus comprising a generator-absorber, a condenser and an evaporator communicatively connected' in operative relation, means to heat said generator-absorber, means for controlling iiow in heat exchange relation to said generator-absorber of a heat abstracting medium, means controlling the heat supplied by said heating means, means controlling said fiow-controlling means, means responsive to predetermined decrease of refrigerant medium in said generator-absorber, a lever operatively connecting said responsive means to said heat controlling means, means responsive to the temperature of said evaporator, a lever operable by said evaporator' responsive means,

clutch means interconnecting said levers and being oberable to transmit movement to said heat controlling means upon increase of evaporator temperature, and means operatively connecting sai-d temperature responsive means to said flow controlling means.

22. A refrigerating apparatus comprising a generator-absorber, a condenser and an evaporator communicatively connected in operative relation, means to heat said generator-absorber, means for controlling flow in heat exchange relation to said generator-absorber of a heat abstracting medium, means controlling the heat supplied by said heating means, means controlling said ow-controlling means, means responsive to predetermined decrease-of refrigerant medium in said generator-absorber, an operating shaft, a lever carried by said shaft and operatively connecting said responsive means to said heat controlling means, means responsive to the temperature of said evaporator, a second lever carried by said shaft and operatively connected to said temperature responsive means, means to transmit movement from said second lever to said first-named lever, and means operatively connecting said temperature responsive means to said flow controlling means.

23. A control device comprising a conduit having a valve port, a longitudinally reciprocal valve member controlling said port, an operating arm, means supporting said arm for pivotal movement, means on said valve memberin the path of movement of 'and spaced from said arm, means operable to move said arm with a quick action to cause engagement of said arm and said valve member means so that said valve member will be actuated subsequent to initial movement of said arm and with a quick movement, and means for initiating movement of said last-namedimeans. 24. A control device comprising a supporting member having a top wall with having a bottom wall and opposed side wall poran aperture and tions, a shaft extending between and supported move said first-named arm to move said reciprocal member in one direction, and a thrust member engageable with said second-named arm and operable through said first-named arm to move :i said reciprocal member in the opposite direction. 25. A control device comprising a supporting member having a top wall with an aperture and having a bottom wall and opposed side wall portions, a shaft extending between and supported l by said side wall portions, an operating arm on said shaft, a reciprocal member engageable and movable by said arm, a second arm on said shaft, means to couple said arms for movement in unison, a thrust member extending through said aperture and cooperable with and operableto move said rst-named arm to move said reciprocal member in one direction, a thrust member engageable with said second-named arm and oplerable through said rst-named arm to move said reciprocal member in the opposite direction, a laterally movable member extending with said first-named arm and from one of said portions. a force-transmitting member positioned between said laterally movable member and said firstnamed arm, and means urging said laterally movable member toward said force-transmitting member so that said last-named means will act to move `said reciprocal member upon movement of said reciprocal member by said last-named thrust member.

26. In a control device, an actuated means, a pair o f actuating means, friction clutch means operatively connecting said actuated means to` one of said actuating means for movement in one direction and operable to render said one actuating means ineffective to move said actuated means in another direction, and means operatively connecting the other of said actuating means to said actuated means for moving said actuated 40 means in said other direction.

27. A control device for liquid fuel burners, comprising a casing having a liquid reservoir with an inlet and an outlet for intercalation in the burner fuel supply line, a reciprocal metering .15 valve controlling iiow from said outlet, resilient meann having a force urging said valve toward closed position, lever means cooperable with said valve and operable to oppose the force of said resilient means, spring means acting on said .3o lever means and opposing operation of said valve by said resilient means, said spring means having a component of force acting on said lever means, said component changing in force upon movement of said lever means to release the force oi.' said resilient means, temperature responsive means, a lever operable by said responsive means, clutch means operable to transmit movement from said lever under the force of said responsive means to said lever means, movement of said 1,0 lever means by said lever acting to release the force of said spring means thereby to overcome said resilient means and open said valve, means responsive to temperature created by the burner, and means operable to transmit movement from c5 said last-named responsive means to said lever means to move said lever means in opposition to the force of said spring means so that said resilient means can move said valve toward closed position. 7U 28. In a device of the character described, conduit means, valve means operable upon movement to control ilow of iluid through said means, temperature sensitive means, lever means operatively connected to said valve means, a lever 75 member operatively connected to said sensitive means for movement thereby, said lever member being operable upon movement in one direction to move said lever means in one direction so that said valve means is moved, means operable upon movement of said lever member in a second direction to render said lever member ineffective to move said lever means, and means for moving said lever means in a direction opposite to said lever means one direction.

29. In a device of the character described, conduit means, valve means operable upon movement to control iiow of uid through said means, lever means operatively connected to said valve means, a lever member, temperature sensitive means operatively connected to said lever member and operable upon increasing temperature to act through said lever member to move said lever vmeans in one direction so that said valve means is moved, means operable to render said lever member upon movement in a second direction ineffective to move said lever means, and means for moving said lever means in a direction opposite to said lever means one direction.

30. In a device of the character described, conduit meansvalve means operable upon movement to control ow of uid through said means,

temperature sensitive means, lever means operatively connected to said valve means, snap-acting toggle means operable upon predetermined movement of said lever means so that said valve means is moved with a snap action, a lever member operatively connected to said sensitive means for movement thereby, said lever member being operable upon movement in one direction to move said lever means in one direction so that said valve means ismoved with a snap action, means operable upon movement of said lever member in a second directionv to render said lever member ineffective to move'said lever means, and means for moving sai-d lever means in a direction opposite to said lever means one direction.

31. In a control device comprising a casing having a liquid containing chamber, said casing l having a valve port in a wall of said chamber, a longitudinally reciprocal valve member controlling said port, an operating arm, means rigid with said casing and supporting said arm for pivotal movement, means on said valve member in the path of movement of and spaced from said arm, spring actuated snap-acting means operable to move said arm with a quick action to cause engagement of said arm and said valve member means so that said valve member will be actuated subsequent to initial movement of said arm and with a quick movement, and means for initiating movement of said last-named means.

32. In a control device, an actuated means, a pair of actuating means, means operatively connecting said actuated means to one of said actuating means for movement in one direction, means operatively connecting the other of said actuating means through said connecting means to said actuated means for moving said actuated means in another direction, said last-named acv tuating means being ineffective to move said actuparatus, comprising a casing having an outlet passageway, a valve member vcontrolling ow through said passageway, a shaft supported on said casing, lever means carried by said shaft and having a portion cooperable with and operable to actuate said valve member, a. pair of iluidcharged temperature responsive power elements positioned on the opposite side of said shaft from said passageway and in lateral relation and be- 10 ing operable alternately to actuate said valve member, a. lever on said shaft, a thrust member operatively connecting one of said power elements to said lever, clutch means for transmitting movement from said lever to said lever means, a second lever cooperable with said lever means, a thrust member operatively connecting said second lever to the other of said power elements, and means cooperable with said lever means to impart a quick movement to said valve member.

EARNEST J. DILLMAN. 

